Being located in a neighboring star system, contact with Vulcan came during the early 20th century. According to the Vulcans, their First Contact with Andorians "seemed promising," "despite their heightened emotions." However, the Vulcans soon came to see them as duplicitous, wishing to only honor "agreements that didn't conflict with their interests." A border dispute, dating back to the 1950s and lasting two hundred years, began between the two powers, due to their neighboring home systems and the Vulcans' suspicion towards the territorial and militaristic nature of the Andorians. The Andorians felt that the only thing that kept Vulcan from invading Andoria was "the threat of massive retaliation." (ENT: "Proving Ground")

In the 2050s, the Andorians terraformed a class Dplanetoid which they named Weytahn, lying at a strategic position on the frontier between the Andorian and the Vulcan system. When Andoria refused to allow the Vulcan High Command to inspect the colony in order to search for possible threats in the form of military installations, the Vulcans forcibly evacuated the planetoid. In 2097, a treaty was signed, in which the Vulcans officially claimed Weytahn, which they named Paan Mokar, and a surveillance satellite was placed in orbit of the planetoid in order to enforce the accord. (ENT: "Cease Fire")

Around 2104, the Andorians discovered the Aenar. Since then, they have maintained diplomatic contact with the Andorian government. (ENT: "The Aenar")

Some time before 2154, the Andorians were also in conflict with the Tellarites. According to Ambassador Gral, Tellarite cruisers had driven "those blue demons" back into their own territory by force. (ENT: "Babel One")

In 2152, Enterprise was able to mediate between the Andorians and Vulcans in their dispute over Weytahn

In 2152, a new open conflict arose on Weytahn, which was reclaimed by the Andorian Empire after being deserted for nearly sixty years. With the conflict about to escalate, Shran, who was leading the Andorian invasion forces on the planetoid, requested CaptainJonathan Archer of the Enterprise as a trustworthy mediator in order to negotiate a cease fire, which was finally accomplished and both sides resumed their negotiations. (ENT: "Cease Fire")

Upon hearing of the Xindi attack on Earth in 2153, the Imperial Guard sent the Kumari under Cmdr. Shran into the Delphic Expanse to locate the Enterprise. When it was discovered that Enterprise was tracking a Xindi prototype weapon, the Guard wished to procure the technology to aid in their conflict with the Vulcans. In justifying their actions, they declared that, "with a weapon of this magnitude at our disposal, they wouldn't dare attack us." However, the prototype was destroyed, forcing the Andorians to go home empty-handed. Before, however, Shran secretly relayed all technical and tactical sensor readings his ship had taken from the weapon to Enterprise; this information would prove to be of enormous use in preventing a second Xindi attack on Earth. (ENT: "Proving Ground") Three months later, Shran and the Kumari openly sided with Earth, following the trail of the Xindi superweapon. The Kumari engaged a Xindi warship, providing a critical diversion to allow Enterprise and her crew to destroy the weapon. (ENT: "Zero Hour")

Starting the Battle of Andoria in 2154, the Vulcan fleet opens fire on Cmdr. Shran's task force and Enterprise

Unknown to the Andorians at the time, the Vulcans had intercepted the data and telemetry that had been sent to Andoria on the prototype. Footage of the Xindi's test of the prototype was later manipulated and used by AdministratorV'Las in convincing the Vulcan High Command that the Andorians were planning to use the prototype to augment their fleet and to create a weapon of mass destruction to use against Vulcan. In 2154, V'Las, who actually stood under the influence of a Romulan operative, ordered a preemptive strike invasion of Andoria and lured the bulk of the Andorian fleet near Paan Mokar/Weytahn by creating false warp signatures in its vicinity, while the Vulcans secretly amassed a fleet of twelve Vulcan cruisers near Regulus, a star outside the range of Andorian listening posts. Despite Enterprise and Vulcan AmbassadorSoval warning Commander Shran of the incursion, the Andorians were only able to gather six warships at the outskirts of the Andorian system to face the Vulcan fleet, with Enterprise joining them in hopes of preventing war. After the two fleets clashed and the Battle of Andoria commenced, Vulcan MinisterKuvak urged V'Las to halt the attack, as even though they were currently winning the battle, they had completely lost the element of surprise and were now facing heavy casualties for both sides in a protracted conflict. Soon after he went on to protest that none of the Andorian vessels were outfitted with the Xindi weaponry that V'Las had used as justification for the preemptive strike, Kuvak managed to stun V'Las and immediately ordered the fleet to withdraw, ending the battle. (ENT: "Kir'Shara")

After the Vulcan Reformation, the Vulcan High Command was dissolved and the new government entered into a less hostile stance with Andoria, ending years of cold war and military tension. Never again did the Vulcans stoop to such a level as using the P'Jem monastery to hide a sensor array for spying on Andoria. (ENT: "Kir'Shara")

Captain Jonathan Archer unites the Andorians and Tellarites in order to form a joint fleet with the Vulcans and Humans

In November 2154, Andorian diplomats planned to meet a Tellarite delegation led by Ambassador Gral on the planetoidBabel. The purpose of the conference was to resolve a long standing trade dispute between both factions. Although the original agenda covered only trade regulations for the sector, the diplomatic situation of the Andorians should change decisively. By late 2154, the Romulan Star Empire had become aware of the threat posed by a closer partnership between Andoria, Earth, and its neighbors. The Star Empire's attempts to destabilize the region led to the Babel Crisis, during which a secret mission by the Romulans involved the use of two Romulan drone-ships. With these ships (able to camouflage themselves as various other vessels), the Star Empire tried to spread distrust and hostility among local powers around Andoria, Earth, Tellar, and Vulcan. By destroying the Andorian vessel Kumari under the guise of a Tellarite cruiser, thereby causing the cancellation of the Babel conference and nearly escalating an old conflict between the two races, the Romulans nearly succeeded with their plans. However, Captain Archer of the Enterprise was able to settle the dispute and allied the Andorians, Humans, Vulcans, and Tellarites to find and destroy the drone-ships, thereby altering the result of this Romulan mission to the exact opposite of what it was intended to achieve. (ENT: "Babel One", "United", "The Aenar")

Talks at United Earth Starfleet Headquarters to form a Coalition of Planets in 2155

With the averted escalation of the Babel crisis, Andoria, Earth and many other worlds realized the value of their joint work and were growing close to founding a Coalition of Planets in 2155. Although this was initially opposed by a xenophobic isolationist group called Terra Prime, Archer was able to make a passionate speech to all members, saying that, as explorers, they should explore the galaxy together. (ENT: "Demons", "Terra Prime")

According to the Last Unicorn Games source book The Andorians: Among the Clans, the Andorian people decided on one icy night in the 17th century to destroy all historical records after a new peaceful faction came to power after nearly a millennia of civil war. This let their people get over the differences that once nearly annihilated their species, and as of the 24th century it was something of a planetary pastime to be a historian, trying to discover Andoria's lost ages (now that their race has matured, and would be able to understand them without risking war).